Toll operator control for telephone coin collectors



M y 24, 1949. G. A, ANDERSON 2,471,037

TOLL OPERATOR comm. FOR TELEPHONE com COLLECTORS Filed April 9; 1946 3Sh eets -Sheet 1- RING/N6 SUPPLY HLAMP-IIIVIIIHI' MA RG/NAL 3 91 g-h. I,3%

L w m t lu 9 Q HM I III 9 99 n mm I AVAIAV g: 3 t

wvs/vron 6.14. ANDERSON ATTORNEY May 24, 1949. e. A. ANDERSON 2,471,087v

TOLL OPERATOR CONTROL FOR TELEPHONE COIN COLLECTORS Filed April 9, 19463Sheets-Sheet 2 FIG 2A a N a I Khan-Am ll L I! lNl ENTOR G. A. ANDERSONLa /MW A TTORNE V y 4, 1949. G. A. ANDERSON 2,471,087

TOLL OPERATOR CONTROL FOR TELEPHONE COIN COLLECTORS Filed April 9} 1946s Shets-Sheet s Q Q Q:

G. A. ANDERSON Lay/aw.

A TTORNEY Patented May 24, 1 949 U NI I'ED S l -ATES is TENT clericsTOLL OPERATOR. CONTROL FOR TELE- PHONE COIN COLLECTORS 1Gustave'AdolplrAnderson, Albany, N .-Y., assignor to-Americam Telephoneand Telegraph Com- ;pany iarcorporation of New York ApplicationTApril"9, 194.6,. Serial No. 660,614

toll-calls originated-at the stati'on andcompleted through the-combinedservices of -a--=-loca1--eX- change-operator and an operator-at adistant toll ofiice.

in telephone systems of I the genera1 typ described above, tollcalls-originating at a coin box station are-extended to their-ultimatedestination *through the combined--services of local andtol1=operat0rs-A'calling subscriber at'a coin box stationoriginates a-toll call intheusual manner, that isyby removing the receiver-zfrom itsswitchhook atthe calling station =and1depo'siting: arcoin-im the coin'receptaclethereat. These operations result in" thetransmission eof 1 aacallsignalto 'thet-local exchange atswhich lthe icaliingi line terminates.The :fA or :answeringnperator atgthedocahoxchange answers the :cail inthe swell-knownmanner. Upon learning the nature of theicalllthedocaloperatorreturnsi-the deposited coinzand connects thecall-ing subscriberwith: theflung;- adistance'1:operator :whoaobtains, from theucaili-ngsubscriber; theztelephonemumbereoitherdesiredrcalled; line. The callingsubscriber; in; certain cases, is thenrequested :to:restol'eathepreceiver zto tits switchhook .and-oisuaiivised-thatrhe (orshe) will .bez'calledcwhen/ -the connection is:r.eady;for :ccmpletion.=.:Thez:details of the call are then passed to a tollv'operatoratitherofiice through whichvtheuconnectionlis:to be extended, --who I thenunder-stakes to complete a connection T110 the --clesired: cal-led;z-line in :wellknown mannerian'd whensuch connection is 'completed, sheselects atoll switching .trunk which extends from= her positiomto the.local' exchange in---Wl1ich'thecalling :line appears and ovenwhichthe-desiredconnectionisrt-o be completed. 1-Sei-z- .zure of this" trunkby"the toll-:operatorsat the distant: oificecauses thexdisplay-of--a-call-signal which identifies .thettrunkoat the localszexchange. Usuallythe incoming *end of'this, trunksappears before .a" iBR operator atthelocal-*exchange-who, noting the .-V-actuated signal, connects :her-telephone ,-set .to the trunk- .and is--requested-by--the tol1--,operator .to complete'za cronnectioncfrom :the .trunkto 'the callingline. The toi1-.switching trunk terminates at the local exchangein.arplug .with Which-the localeoperator tests the, jack. mul- ,.tiple=ofthe calling line -and,'.-findingn-.theline .idle, .inserts the plug into.vthe jack amultiple. -Upona connect-ion of :the stallswitch-ingttr-unki to '2 operators position is actuated whichserveseas aringing signal to'the toll operator. Thefl-toll operator .then signals,outnoyerlthetoll. switching trunk to cause. the actuation. of thesignaling I device at "the calling station. "Whenwthe scallingsubscriber respondstothis signal he (or she) is requested to depositthenecessary.toll inicoins, in the coin receptacle; provided, for. thispurpose. While the "traffic justtdescribedlmay Vary under certain.conditions, it follows :an vaccepted-,.:procedure.

Usually, the deposited coins are collected-Apr refunded, as required,at; the termination; of...conversation between the calling-andscalled,-,-par.ties, assuming .the time. consumed on the-connection doesnot exceed the prescribed initial t period. Generally these coincontrolioperations=aretper- .-formed by the operator at -the \l0oa1\exchange ,atztheidirection of the tolhoperator.

It a is the objectof the present sinventioncto provide facilities, in atoll :"switchingzatnunk, which enable the, coin controlpperationseordinarily performed by a -local, operatorgytoxbcizp rformedby the toll, operator :1 atwthetdistant :ex-

change. a

This l object is attained, i in accordancefwith .-a particular ,-feature:of the inventions-Joy ithGs-PEO- visionqofa toll switchingtrunknwhichembodies a voltage responsive device, cor, vacuum 1 tube; i-neachof t the outgoing l-and-rincoming ends -ofi the ltrunk,.the formerof which functions imresponse \toJthe application of coincontrol:battery-ltohthe .tip conductor of the.trunk.-.;by. thBLtOJ-lioperator -to super-impose on wthe. trunk s vsim'plex circuit,.andito-extend-thetip conductor of ithe outgoing ;end;.of the trunkthereto.to:cause'ithentransmisr sion of coin control wcurrentovermtheztip and .ring conductors. ofithetrunk,*: in parali-el; to-atheincoming ,endrofzthe trunlcat the: local exchange. \The a vacuum tube in[the incoming end wOfuthG trunk responds to the (transmittedicoinrscontrol ,currentland controls-the connection of 1118x001.-iresponding, coin control: batterysat thedocakex- .change .tothe:calling,lineitotcauseua; correspond- ;ing: coin ccntrol i'unction=.to.: he eperformedzby-"the coin magnet-.atthe calling-station. thisman- .ner-:theoperatorzat the local:exchangeisisrrelieved inf :s-iiheduty of performing zthe .ne'cessaryeicoin control operations: and suchoperationszare placed under the direct control:EOfjlthBttflllilfilPB'IEtOlYlEt the distant-toll. .-board.

n-zThis. and 10131181) featureswof zitherinventionz vwiil .beebetteriunderst-ood irom theliollowingrrletaiied ,the' calling lineatsupervisory isignal atr-thez -,to1l n .descriptionwhensreadginzconnection with-thoraccompanying drawings, in which:

Figure 1 is a circuit diagram of a toll cord circuit located at adistant toll ofice, together with certain portions of the position andcoin control circuits which function with the toll cord. Only thoseportions of the cord, position, and coin control circuits which areessential to a complete understanding of the invention are illustratedin this figure;

Fig. 2A is a circuit diagram of the outgoing end of a toll switchingtrunk arranged for sleevetype supervision and which embodies features ofthe invention;

Fig. 2B is a circuit diagram of the outgoing end of a toll switchingtrunk arranged for bridgetype supervision and which embodies features ofthe invention;

Fig. 3 is a circuit diagram of the incoming end of the toll switchingtrunk which functions with each of the circuits shown in Figs. 2A and2B. This figure also shows schematically a sub- H scribers lineextending to a and Fig. 4 is a block diagram showing the manner in whichthe other figures of the drawings are to be assembled to effectoperative systems.

In the following descriptions it will be assumed that a subscriber atstation A has originated a toll call; that the answering operator at thelocal exchange has passed the necessary information to the toll operatorat the distant toll office in the well-known manner and as outlinedhereinbefore; and that the toll operator has completed the other end ofthe desired connection and proceeds to complete the originating end ofthe connection by the insertion of the toll cord front plug 90 into thejack M of the toll switching trunk extending to the local exchange.

When the toll operator has completed the other end of the connection tothe called line she inserts the front plug 90 of the toll cord into jackM of the toll switching trunk whereupon a circuit is completed extendingfrom grounded battery, winding of sleeve relay 91, upper winding ofsleeve relay 92, normal make-before-break contacts of relay 93, sleevecontacts of plug 96 and jack [4, lower winding of relay l5, to ground.Relay 9| operates in this circuit but relay 92 being marginal does notoperate owing to the high resistance of the sleeve circuit.

Relay 9| in operating completes an operating circuit for relay 94 toground at the armature and back contact of relay 92. Relay 5% inoperating locks to ground at its middle upper armature and front contactunder the control of relay 9!, thus remaining operated independent ofthe condition of marginal relay 92. At its two lower armatures relay 94opens the ringing leads from the alternating current supply 95 to theringing key 95 and connects the direct cur-- rent source 91 to the tipspring of ringing key 96 by way of the outer lower armature and frontcontact of relay 94. At its outer upper armature relay 94 opens thecircuit to relay 98 and at its innermost upper armature and frontcontact connects the winding of relay 93 in parallel with the uppersecondary winding of relay 99.

In the outgoing end of the toll switching trunk relay l5 operates in theoriginally traced sleeve circuit and completes an obvious operatingcircuit for slow operating relay I6 Relay l6 operates slowly in thiscircuit and at its armature and front contact connects the winding ofrelay I! to the line side of repeating coil T for receiving signals fromthe local station A and transcoin-boX station;

4 mitting them to the sleeve circuit of the toll cord.

With relay ii bridged across the trunk conductors 2d and 28, relay 2% inthe incoming end of the toll switching trunk operates. The operatingcircuit for relay 20 may be traced from grounded battery, lower Windingof relay 2E3, contacts ill of relay 22, upper winding of relay 23, lowerleft winding of repeating coil T2, ring conductor 24 of the trunk, innerlower armature and back contact of relay 25, lower right winding ofrepeating coil T, lower armature and back contact of relay 25, frontcontact and armature of relay l6, winding of relay ll, back contact andupper armature of relay 26, upper right winding of repeating coil T,back contact and outer upper armature of relay 25, tip conductor 28 0fthe trunk, upper left winding of repeating coil T2, lower winding ofrelay 23, back contact and outer armature of relay 22, upper winding ofrelay 2%, to ground. Relay 2t, operated, completes an obvious operatingcircuit for relay 36 which finds battery at the outer lower armature andback contact of relay 3|.

Relay 22 also operates under control of relay it? in a circuit which istraced from grounded battery, lower winding of relay 22, outer upperarmature and back contact of relay 3!, upper Winding of relay 22, toground at the armature and front contact of relay 2t. Relay 22,operated, disconnects battery and ground supplied through the windingsof relay '29 from the ring and tip conductors of the toll switchingtrunk towards the distant toll board and connects the lower winding ofrelay 29 to direct ground at the inner armature and front contact ofrelay 22 thus holding relay 2B operated and releasing relay I! at thedistant end of the trunk. It will be understood that when relay H wasfirst bridged across the trunk it operated together with relay 2i) and,in operating, connected the upper winding of relay it in shunt with thelower winding thereof to decrease the resistance of the sleeve circuitin the toll cord TC. With this decrease in resistance marginal relay 92operated and completed an obvious energizing circuit for the supervisorylamp tilt at the toll operators position, in which circuit the lamp islighted. When relay l1 releases, as described, the original sleevecondition is restored and relay 92 releases its armature causing thesupervisory signal wt to be extinguished.

When relay 3% operated as previously described it completed a lockingcircuit for itself by way of its lower armature and front contact, andat its upper armature and front contact it completes an intermittentlyenergized circuit for the guard and disconnect lamp signal 33 at thelocal exchange. This circuit may be traced from grounded battery 34,interrupter 35, upper armature and front contact of relay 393, backcontact and inner upper armature of relay 3!, filament of lamp 33, toground. The lamp 33 flashes in this circuit as a call signal at thelocal exchange.

The answering B operator at the local exchange upon noting the flashinglamp signal 33 associates her telephone set (not shown) with the trunkby the operation and. release of the nonlocking talk key whereupon relay3'1 operates in a circuit extending from grounded battery, inner lowerarmature and back contact of relay 3!, lower winding of relay 31, toground at contacts of key 35. Relay Bl locks to ground through its upperwinding and all talk keys of the position when key 36 is released. Thetalk keys names? of the position, other than key 36; have notnbeenillustrated therlock-ing; ground .howeveris indicated at 38. ".Amongwthefunctions performed bylrelay this the connection of'the operatorstelephone-set-;(not shown) tothe trunk iorcoml-munication.Othersfunctionszperformed by relay '3? need not be described sincetheirdescription isnotnecessarytc a complete understanding of theinvention. The 53 local operatorthen .as- 'ce'rtains. from thetolloperator 'th -number of the line :with whichitheplug l of thevtrunkistotbeconnected and having done so;touches .the tip of. plug [0 to thersleeve=of .jack i2 for .test purposes in. the well-known; manner.Assumingthe calling subscriber at station A bad. restoredthereceiver toits switch-hook after originating thezcall to the local .A operator,the. line would testxidle and the local B operator would theninsert;plug ifl into the .jack multipletlz and cause the release of key 46. At.itsllower alternate-contact key-:40 completes an obvious operatingcircuit for relay 3| and at its upper alternate .contacts extends thetipof plug 'illlto .the inner upper armature of relay 4|.

azRelaySi, operated, extinguishes' the guard .anclpdisconnectv lamp.33.and opens the holding :circuit for relay 3'! whereupon this relayreleases :andzdisconnectsthe operators telephone set (not shown) from:the trunk. Relay 3|v also opens the circuit .to relay 22 causing thisrelay to release and' reconnect battery and ground to the trunkthrough-the windings :of. relay 26. This causes .relay ii to operate andlight lamp we as a ringing signal to the toll. operator.

:The tool 'operatornow signals the calling: station- A by actuating key96 associated with the ;fr-ont-end of ithetoll cord TC. When this isdone a 'circuit is completed from :the 48-vo1t :batterydl'l; frontcontact and outer lower armature of relay 94,.upper alternate contactofkey a96ntipicontacts of plug '90 and jack I4,\back contactandvouterlower armature of relay '25, upper left winding of repeating coilT,.upper winding of:v marginal relay L63 and parallelly connectedresistance '64, back-contact and armature of -relay ,l33,-'Winding ofrelay 26, retard coil 65, to ground at the armature and back contact ofrelay Z62. r-Relay 63 does. not operate at this :time. Relay- 26,however; operates and connects the "ringing supply 5 to the line side ofthe repeating -c.oil T andthence to ttrunkiconductors 24 and 28 byrwayofthe Joack contacts and the inner lower and outer upper armatures ofrelay 25, through .theleft windings of repeating coil T2, condenser4.1and'the winding .of relay 8. Relay26 also disconnects :the winding ofrelay ll from the trunk ,:causing:the lamp airtll to be extinguished.Relay 8- responds to the'current from source 9 and at :its armature andfront contact completes an obvious operating circuit for. relay 1. Relay)1 :operatesandat its two outer armatures opens ithetipwandringconductors towardsrepeating coil 'T2.- and connects the-ringing currentsource 6 :to :the tip: and ring contacts of plug it] by way iofzthe backcontacts and the upper and lower .armatures of relay 4|. 1 At its innerupper armarture andfrontcontact relay '1 reoperates relay 22.The-operation of relay '22 holds relay 26 operated ith-roughi itsv lowerwinding. 1 When ringing curirent isdisconnected from the trunk at thedistant tool position relay 8 releases,.in turn releasing .Rel ys I"which releases, relay;- 22. #:Relay. 1, re-

leasedr disconnects jringing current;- from -:=the rstaticmA. :The.areleasezof relay 422 relightszthe i011, operatorssupervisqryrsignal4'06in eta-manner previously described andmndermontrol Iof relay l 1 whichis-reconnected to the:trunlnrwhen relay -2 fi releases incident to thetlisconnection 0f battery 91,

' It will be observed that when' relay' H-ooperates as described aboveitdisconnectsrelay from the-tip and rink c-onductors of thetrunkithereby removing th low resistancewhich shunts vacuum -in therelease of relay I I "andthe consequent 'release of marginal "relay 92inthe 'toll -cord.

" The toll operatorthenrequestsithe subscriber at station A 'to depositthe prescribed tariff, for the desired-calk-in coins in "the coin box"at the substation.

Conversation between the calling party "at station A andthe"called;.party' maynow take 'place,it being understoodfthattheconnection tothecalledline has beeneompleted by,'the 1:011 operatorinany well-known manner.

. It will now.be assumed that'theitime has .come

.atwhichit is necessary forthe toll .operatorjat the distanttoll"boardyto'collectfthe coinsdeposited atthe coin box subscribersstation A, and

"itwill further be assum'dth'ahthe lreceiveris still off the switchhook,at the substation.

I'With'the receiver ofitheiswitchhook, at station A relays 43;"22,"20;'30'. and3l are operated. .To

collect .the: coins the; toll"'; operator1first. actuates key '1!!!and'then operates'fthe coin collectpkey I02 in the position circuit.'.'When .key 'llll...is operated to v the talk;position,"v it being,understood ithatponly those portions 'of "thekey. which are essential.to theipresentinvention are illustrated inthe drawing, relay 59.operates, ina circuit extending from grounded" battery, lower winding ofrelaySQ; contactsflmv .of key ljlllLlto ground atthe inner armaturecandback contact of relay I64. Atitsinner' lowernarmatureand --frontcontact;relay '99 connects ground atcontacts I05 of key .IOI. tolbattery andground through the winding "of slow'operating relay J64 so that relay m4operates and; at its upperarma- =ture and front contactnompletes alockin 'circuit for relay '99 which tie/completed beforethe originalenergizing circuit for relay 99 is opened. At its two outerarmatures'relay 99'splits the toll cord; and at its outer-upper armatureand front contact connectsthe'tip-contact of plug-9n tothe 'coin controlkeys I 02 and' I UB.

"With the plug -'of the toll cord plugged into jack J4 of'thetollswitching :trunk relays 'l5and H5 in the outgoingendbf'thetruhk areoperated,

.as described, as are alsmr'elays 9| andMin the toll. cord TC. Wherl"key I 0 I is operated; relay .93: operates ina circuit extending fromgrounded battery, winding of relay 93; -front-contactand :innermostupperarmature-bf relayfl front con- ..tact...and= inner i upper armaturel of relay flll to ground at the. upper armature and front contact .ofrelay 7| 04; in v the, positionfcircuit. At itsupper armature and:frontcontaict relayli93 removes the -;relays stand; 9 I' fromltheii'sleeveaicircuit pf the march and connectsithemtr thmnghitheresistanee I 08 to ground at the armature and back contact of relay I09,the resistance I08 simulating the sleeve resistance of the outgoing endof the trunk. Relays 92, 9| and 94 accordingly are not disturbed by theoperation of relay 93 as the changeover is effected by way ofmake-before-break contacts of relay 93. At its lower armature and frontcontact relay 93 connects the sleeve of the front cord to battery andground through the windings of marginal relay Ill) and of relay III, theresistance of which relays simulates that of relays 92 and 9| which wereoriginally connected to the sleeve of the front cord. The resistance I08insures a circuit for the front cord relays 92 and 9| from the time thefront sleeve is transferred until relay I I I operates which it doeswhen relay 93 operates, as described. When relay III operates it causesrelays I99 and I99 to operate. Relay I99 maintains ground on resistanceI08 to hold the cord sleeve relays.

When coin collect key E02 is operated, llll-volt positive coin collectbattery I I2 is connected to the tip of the front cord over a circuitwhich includes the filament of resistance lamp i5l, winding of relay H3,closed contacts of coin collect key I02, normally closed contacts ofcoin return key I06, front contact and outer upper armature of relay 99,back contact and inner upper armature of relay 98, upper normally closedcontacts of key 96, tip contacts of plug 99 and jack I l to the point60, and thence to ground over two parallel paths, one including thevacuum tube or space discharge device 6! and the winding of relay 62,and the other including the upper left Winding of repeating coil T,upper winding of marginal relay 63 and the associated parallellyconnected resistance 54, winding of relay 26 and retard coil 65.

Under certain resistance conditions of relay 26 the retard coil I55 andcondenser 66 may be omitted and have been shown as means for improvingthe performance of the circuit when the resistance of relay 2G is belowa certain prescribed limit. Retard coil 55 increases the impedance ofthe tip circuit which tends to reduce acoustic disturbances when thecoin control battery is connected to the tip of the circuit. Theinductive reactance of the retard coil also produces a momentaryincrease of the eifective potential applied to vacuum tube when the coincontrol key is oprated. Condenser 65 lowers the breakdown impedance toground of the vacuum tube circuit.

Similarly, marginal relay 63 and resistance 64 may be omitted beingrequired only when the shunting effect of the circuit through relay 29to ground prevents reliable operation of the vacuum tube 6i and relay62. Relay 53 is marginal and will not operate over its primary windingin parallel with resistance 64 when 48-volt ringing current is appliedto the tip of the trunk. When llO-volt positive or negative coin batteryis applied to the tip of the trunk relay 53 operates over its primarywinding in series with relay 221. Relay 63, operated, removes the shortcircuit from its secondary winding and short-circuits the winding ofrelay 26 which immediately releases if it has operated before the backcontact of relay 63 is opened. Relay 63 holds over its high resistancesecondary Winding which is inserted into the circuit to ground over thetip of the trunk. Vacuum tube iii and relays t2 and 25 will thenfunction in the manner to be presently described.

The resistances of the circuits previously traced are so selected thatwhen the 110-vo1t coin collect battery H2 is connectedto the tip of thetrunk incident to the operation of coin collect key I02, the effectivepotential applied to the tube BI is sufficiently high to break down thecontrol gap of the tube. Current then flows across the control gap tocause the operation of relay 62.

Relay 62 operating, disconnects ground from the winding of relay 2S andoperates relay 25 over an obvious circuit. Relay 25, operated,disconnects the tip and ring conductors of the trunk from repeating coilT; connects the series resistances I0 and 'lI across the tip and ringconductors 28 and 24; disconnects the switchboard side of repeating coilT from the tip of the trunk; and connects the tip of the jack I4 to themidpoint of resistances l8 and H. The coin control current from batteryII2 will then flow through resistances I9 and II over the tip and ringconductors 23 and 2 3 of the trunk in parallel to the incoming end ofthe trunk (Fig. 3) at the distant local ofice.

The parallel paths for the coin collect current from battery iii may betraced from the midpoint of resistances iii and It as follows:resistance i9, tip conductor 23 of the trunk, upper left winding ofrepeating coil T2 to the point 3, and resistance ll, ring conductor 24of the trunk, lower left winding of repeating coil T2, to the point 2.It will be observed that at this time the ring connection from point 2is opened at the contacts 2i of relay 22 which relay, as previouslyindicated, is operated. The direct current path through relay 8 isblocked by the condenser 4. The path over the tip conductor just tracedto the point 3 is connected to ground through the lower winding of relay23, vacuum tube 73, and the windings of relay I 3 and I5. Though relayH3 in the coin control circuit at the distant toll board is included inseries with battery II2, the resistance of the circuit just traced andafter the break down of tube 13, as will be described presently, is toohigh to permit this relay to operate so that the lamp signal H5controlled thereby does not operate.

When llO-volt coin collect battery H2 is connected to the tip and ringconductors of the trunk, as described, the ellective voltage applied tovacuum tube is over the tip of the trunk causes the control gap of thetube to break down and current flows across the gap to cause relays I4and 15 to operate in series. Relay i4 is a neutral relay and operates oneither positive or negative potentials, whereas relay l5 is polarizedand will operate only on positive potentials.

When relays ii and 75 operate, relay I4 operates relay It which closesan obvious holding circuit for relay 22, and relay 35 operates relay 11,which connects 1l0-volt positive coin collect battery it to the windingof relay I9 and, at its lower armature and front contact completes anoperating circuit for relay t I.

At its two inner armatures and front contacts relay l! connects the-volt battery I8 through relay ill to the tip and ring contacts of thecalling line by Way of the corresponding contacts of plug I9 and jackl2. At its outer upper armature and front contact relay lI connects thetip and ring conductors 20 and 24 of the trunk in parallel through thewindings of relay 23. At its two inner armatures and back contacts relayiI disconnects the tip and ring of the trunk circuit cord from repeatingcoil T2.

It will now be observed that, with the shortcircuiting of vacuum tube I3and the interconnection of the tip and ring conductors through thewindings of relay 23 by the outer upper armature and front contact ofrelay 4!, the parallelly connected'paths find ground through the seriesconnected relays i i and 15. As will be indicated presently theresistance of the path over which the coin collect current passes iscontrolled by coin supervisory relay 79 which operates if a coin ispresent for collection in the coin box at station A and does not operatein the absence of a coin. In th'eunoperated condition of relay IS theresistance of'the circuit is high and the relay H3 in the coin collectcircuit does not operate.

Assuming the calling subscriber has deposited coins in the coin box atstation A as directed by the toll operator, ground 80 through the coincontacts 8| and the winding: of coin magnet 82 will be connected to theline at the station. Coin collect current from battery 18 causesmagnetflz to operate and collect the deposited coins in the well-knownmanner, and causes relay is to operate. Relay l9, operatcd,short-circuits vacuum tube'lS and connects resistance at to ground inparallel with the windings of relays it and 15. The vacuum tube 13 isshort-circuited to prevent relays l4 and i5 from releasing when shuntedby resistance 84.- The coin control current from the battery I I2 at thetoll ofiice through resistance 84 inl-parallel with relays i l and 55holds these relays operated and the circuit resistance is reducedthereby causing relay H3; in the coin control circuit to operate. RelayI 13, at its armature and front contact completes an obvious operating.circuit for lamp signal H5. Relay 23 also operates on this coin collectcurrent and connects a holding ground to relay Hi.

When the toll operator releases the coin collect key H32, relay H3 isdeenergized and lamp signal H5 extinguished. The release of key I02removes coin collect battery H2 from the trunk conductors causing relays23, M and E5 to release. Relays 62 and 25 in the outgoing end of thetrunk also restore their armatures when key I02 is restored.

Relays 23 and i4 releasing, open the circuit to relay 16 which relayreleases after a slight delay. Relay '55, released, causes relays ll andH to release. Relay ill on releasing, disconnects negative coin controlbattery 8'! from the back contact of relay Tl;- disconnects coin controlbattery from the coin box line; disconnects the ring conductor of thetrunk from the vacuum tube cirwit; and reconnects the trunk cordconductors to repeating coil T2. Relay i9 is also released.

The operator at the toll office can verify the disposal of the coins atthe coin box station by operating the coin collect key I02 a secondtime. The circuit again functions as previously described. However, ifthe coins have been collected the! coin magnet 82 will not be connectedto ground at the coin box station and there will be no path for the coincontrol current to ground at station A. Therefore, relay is does notoperate and the lamp signal at the toll ofiice fails to light.

Supervision from the calling line is obtained when the key Iii! in thetoll cord TC is in its operated condition under control of the marginalrelay 1 ill in the position circuit. It was hereinbefore described howrelay Hi operated over the sleeve circuit of the cord and outgoing endof the trunk. Relay I it though connected in series with relay HI didnot operate at that time. When the receiver is replaced on theswitchhook atstation A, relay is. releases, causing the release ofrelay. 22 which reconnects battery and ground to the ring and tipconductors 2A and 2B of the 10 therefor operates and atits armature andfront contact connects the upper winding of relay It: in parallel withits lower winding thereby reducing the resistance of the sleevecircuit-and causing.

- relay lit to operate. Relay H8 at its armature and front contactcompletes a circuit, which includes resistance M9 for the operation ofmargi1-- nalrelayez which completes an obvious circuit for supervisorylamp me;

When the plug 93' of the toll cord is removed from. theoutgoing. trunkjack M at the distant end of thetrunk, relay 20 in the incoming endv ofthe trunk releases. The release of relay. 20"" releases relay 39. Relay3D, releasedycauses the flashing of the guard and disconnect? lamp 33 asa disconnect signal. The plug H] of the trunk cord is then removed fromthe multiple jack l2 of station A, and hey w is reoperated whichre-'-.leases'relay 3i causing the lamp 33' to be extinguished and restoringthe circuit to normal:

I-Iadv the party at station A restored thetrecciver thereat to itsswitchhook at the terminae tion of the call prior to the initiation ofthe coin collect operation by the toll operator, relays 43": and 22would have released and relays 28', 30 and 3| would be operated. Relay2% does notoperat'e in series with relay 25 because the windings ofrelay ESoppose each other under this condition; When i Iii-volt coincollect b'atery l i2 is connected to the tip and ring conductors of thetrunk atthedistant toll oflic'e, relay 23ioperates in series with relay2B. Relay 23' operates relayflfi whichjin turn, operates relay 22. Relay22 operating,,dis connects relay 20 from the trunk and connects groundto the lower winding of relay 2b to hold) this relay operated. WhenrelayZilflis discon-jl nected from the trunk the windings of. rela'y'23' areopened causing relay 2? to release. Relay (6. being slow releasing holdsuntil relay M operates, as previously described, and again closes theop: erating circuit for relay 1B1 The operation of relay 22 removes. theshunt. from vacuum tube 13, thus increasing the voltage" applied to thetube so that the control gap of the tube will breakdown. Current willthen"fio'w '1' through the tube to operate relays M and E5: The. circuitthen functions in the manner: previously.

described.

When the coincollect battery ,is disconnected".

from the trunk at the toll office the. circuit functions as previouslydescribed. When relay." re-"- leases under this condition relay 22isreleased, leaving only relays 26, til and 3t operated.

Fig. 2B differs from Fig. 2A in that the former illustrates the outgoingend of a toll switching trunk-arranged for bridge supervision whereasthe latter illustrates the outgoing end of a toll. switching trunkarranged for sleeve supervision. The incoming end of the trunk showninFig. 3" functions with either of the outgoing ends shown. in Figs. 2Aand 2B;

When the toll operator at the distant toll oifice I inserts plug 96 intojack'l zil of the toll switching trunk, Fig. 2B, relay [2| operatesthrough its low resistance winding over the sleeve circuit of" the trunkand toll cord TC in the same manner as did-relay l5 of the trunk. ofFig..2A. At its armature and front contact relay l2! connects relayiZZto the right windings, or the local sidei of repeating coil T3across thetip and ring con ductors 123 and-I24 by way of the back contacts andouter upper and lowerarmatures of relay I25 andthe back contacts andarmatures of rc= layififi. The lowresistance of the sleeve of the tollswitching trunk through the windings of relay trunk allows. relays 92and .9 I in. the cord sleeve circuit to operate. Relays 92 and9I'operate ap- 23." Relay H in the outgoing end of the trunk proximatelyat the same time and therefore do not permit relay 94 suflicient time tooperate. Relay 92 at its front contact supplies ground through thearmature and back contact of relay II 6 for lighting the supervisorylamp I and supplies ground through the back contact and outermost upperarmature of relay 94 for operating relay 08 which cuts in the repeatingcoil T4 and supplies talking battery and ground to the trunk through thewindings of relay H6 and the windings of the repeating coil T2. Relay 9%also closes a circuit from key IOI through the windings of relays H0 andIII in the position circuit.

With relay I22 now connected across the outgoing end of the trunk by theoperation of relay' I2I, the former relay is prepared to receivesupervisory signals. In its unoperated condition relay I22 connects theretard coil I 27 across the jack side of repeating coil T3 so that relayI I6 operates to open the circuit to the cord supervisory lamp I00.

With relay I22 connected across the local side of repeating coil T3,relay 20 in the incoming end of the trunk operates and causes relays 22and 30 to operate as previously described. Relay 22, operated,disconnects battery and ground supplied through the windings of relay 20from the ring and tip of the trunk, and connects the lower winding ofrelay 20 to ground, holding relay 20 operated and extinguishing thesupervisory lamp I00 at the toll operators position by causing relay I22to release and complete the operating circuit for relay I I6.

Relay 30, operated, lights the guard and disconnect signal 33 fromintermittent battery supplied from battery 34 by way of interrupter 35causing the flashing of lamp 33.

The call at the local exchange indicated by the flashing of lamp 33 isanswered in exactly the same manner as previously described, by theoperation of key 36 which causes relay 3! to operate. The functionsperformed by relay 31 have been fully described hereinbefore. Whenadvised by the toll operator to connect with the line of station A, thelocal operator touches the tip of plug I0 to the multiple jack I2 of thedesired line to make the usual busy test. If the line is found idle thelocal operator inserts plug I0 into jack I2, it being understood thatafter the busy test is made, the test key 40 is caused to be released toextend the tip conductor of sta tion A to the inner upper armature ofrelay 4| and to complete an obvious operating circuit for relay 3|,which relay operates and extinguishes the lamp 33. Relay 3! alsoreleases relays 37 and 22.

With relay 22 released, battery and ground are connected to the ring andtip of the trunk through the windings of relay 20 causing the operationof relay I22 in the outward end of the trunk. Relay I22 operated, opensthe energizing circuit for relay II 6 which relay releases its armatureand thereby causes supervisory lamp I00 at the distant toll operator'sposition to be lighted as a ringing signal.

To signal out over the line on which station A is located the tolloperator actuates key 96 and either the W or J party ringing keys I30 orI3I. Key 96 extends the tip and ring conductors of the front cord to thecontacts of the party line ringing keys by way of the two lowerarmatures and back contacts of relay 94, the ringing keys beingconnected to the ringing current source 95 in the well-known manner andas indicated in the drawing. With the W party ringing key I30 operatedground is connected to the tip conductor of the trunk and thealternating current terminal to the ring conductor so that vacuum tubeI32 is at ground potential and therefore will not function under thisringing condition. If the J party key hill is employed, negativesuperimposed ringing will be connected to the tip conductor and groundto the ring conductor of the trunk. Under this condition the control gapof vacuum tube I32 will break down on the ringing current and relays I33and I25 will operate. However, relay I34 will also operate, in turnoperating relay I26, which disconnects the trunk conductors from relayI25 and connects the continuous ringing current source I35 to the trunk.Relay I25 is made slow to operate in order that the relay I26 mayoperate first under this condition.

Assuming the W party ringing key I30 is operated by the toll operator,relay I36, responds to the ringing current connected to the trunkthereby and causes relay I26 to operate and project ringing current fromthe source I35 out over the trunk conductors I23 and I24. Relay 8 in theincoming end of the trunk thereupon operates and causes relay I tooperate over an obvious circuit. Relay 'I, as previously described,reoperates relay 22 and connects the ringing current source '6 to theline of station A to cause the actuation of the ringer thereat. Relay 22holds relay 20 operated.

When the toll operator releases the ringing key at the distant tollposition, relays I32 and I26 in the outgoing end of the trunk willrelease causing ringing current to be disconnected from the trunkconductors. Relay 8 in the incoming end of the trunk then releasescausing the release of relays and 22. Relay I disconnects ringingcurrent from station A. The release of relay 22 reconnects battery andground to the ring and tip conductors through the windings of relay 23to cause the operation of relay I22 in the outgoing end of the trunk.Relay I22, operated, opens the operating circuit for relay Ilfi whichrelay thereupon releases, completing an obvious energizing circuit forsupervisory lamp I00.

When the party at station A removes the receiver from its switchhook inresponse to the incoming signal, relay 43 operates over the closed lineloop at station A and causes relay 22 to operate. Relay 22, operated,locks relay 20 operated and opens the ring and tip conductors of thetrunk to battery and ground through the windings of relay 20. Relay I22in the incoming end of the trunk thereupon releases and reestablishesthe operating circuit for relay H0 in the toll cord. Relay H8 operatesand extinguishes the supervisory lamp I00.

The toll operator then requests the calling party at station A todeposit the required amount of coins in the coin box and conversationbetween the calling and called parties may proceed.

When it becomes necessary to collect the coins deposited at station A,the toll operator actuates the key iIlI in the toll cord TC and followsthis by the operation of coin collect key I02. Relay 99 then operates ina circuit extending from grounded battery, lower winding of relay 99,contacts Hi3 of key IiII to ground by way of the inner armature and backcontact of relay I04. At its inner lower armature and front contact,relay 99 connects ground at contacts I05 of key IIlI to battery andground through the winding of relay I24 so that relay I M operates and,at its upper armature and front contact, completes a locking circuit forrelay 99 which is completed before the for relay- 994s openedzftol-lcord and at. its outerrupper armature con-- nectsvthe' coin controlkeys" IIlB'and 102: to the: uppeirbackcontact circles-:98; Whencoincollect.- key-LI I32: is operated; ground by way of con tacts"v l ifi ofkey I532 and-contacts M2 of key IN is. connected to the 'upper' windingof relay 88 threbyshu-nting .itand causing the relay to releasez'. Therelease of relay Q8: extends'the said 1 upperlback contact :thereof"to'the tip of plligififl, thence-overthe tip oft jack I2 9;- vacuumtube I32; to ground through the winding of relay I33; Thus:

withikeys'il 6i and I I121 operatedthe llc-volt' coin collect battery '2:is connected to the vacuum tube 132 and this voltage causes the controlgap i of tlietubetoibreakdown and 'currentlthenflovv' s' across thecontrol :gap to :ground through the winding of relay 133$ R lay I33operates on this current and, in turn, causes relay I25 to operate;

Relay Ifijat its two outer-armatures and back contacts disconnectsrepeating coil T3 from the trunk-conductors I 2 3" and IZQ and 'at-'the-=tWo'-' corresponding frontcontacts connects resistances Ifli andI 4? across these conductors. At its inner upper armature'andfrontcontact relay E25 connects the tip ofj ack -I 26" to the mid-pointof re sistanc'es lefi "and-t ll? Thuscoincol-l'e'ct current fronr thebattery I I2- isprojected over-the trunk conductors IZS and-"IZ E to theincoming end-of the tollswitching-trunk to control the connec tionof-coi-ncoll'ect battery'lB to the calling line in the manner previously-described. The operation of the circuitof'Fig. 3 in'response to theapplication of coin control current thereto has been fully describedhereinbefore and need not be repeated at thistimel Suffice it'to saythat if contacts BI are closed to ground through a deposited cointhe-trunk resistance is reduced by the operatioit ofrela'y- I9tocause-relay I I i; inthe coin com trol'circuit'at the distant exchangeto operate and light the pilot lamp H5 and the coin magnet 82 to collectthe deposited coins. If no coin is in position to be collected thecontacts iii are opened and relay I9 does not operate so that relay H3fails to light lamp I I5.

When the coin collect key I02 is restored to normal relays I33 and I25release. If the key is operated a second time to verify the collectionof the coin the circuit again functions as described. However, if thecoin has been collected the pilot lamp I I5 will not light.

In each of the preceding descriptions the collection only of coins hasbeen considered. If the conditions called for the refunding of thecoins, coin-return key I06 would be actuated in place of coin-collectkey I02 to connect 110'-volt negative coin-return battery I48 and relayI49 to the tip circuit. The operation of the circuits is the same ineither case except that in the return of the coins only relay I4operates while polarized relay 15 remains unoperated so that relay TIcannot operate. The 110-volt negative coin-return battery 81 at thelocal exchange is connected to the calling line by way of the backcontact and upper armature of relay 11, which relay, as just indicated,does not operate when the deposited coins are to be returned.

Supervision is obtained in the case of the trunk circuit of Fig. 23under control of relay I22. Disconnection is effected in the Well-knownmanner and description of the circuit operations resulting therefrom isbelieved unnecessary.

What is claimed is:

1. In a manual telephone system, a toll office.

- line with said toll oifice by way of said local-:oflicefi sources ofcoin control current at said local oflicej' similar sources of'coincontrol currentat said toll ofii'cej'means-atsaid toll officeforconnectihg one ofzthe' said sources-thereatto the tip, condu'ctor roft saidtrunk, space discharge means responsive to the" connection ofthe said one ofv said sources". to the tip conductor of said trunkforprojecting current from said source to said local oflice-over:the-tip i and ring conductorsof saidtrunh and: space discharge means atthe local oflice respon si-ve-to the-projected current from the said oneof' said 'sources at said toll ofiice for 'connec'ting a:- correspondingone of the sources at" saidlo'cal ofiice to said line to effect acorresponding opera =tion of thecoin disposal means at said pay station}'therewith; a toll switching trunk connecting said line withsaid tolloffice byway of said local ofiice,

source of coin control currentat said local oflice',"

a 'source'of' coin control current-at said toll office," means at''said'toll office for-connecting the coin control current source thereatto one conductor of said-trunk, aspa'ce-discharge device in' said"trunkat said toll office responsive to the connection ofthe' said sourceof *coin control current to: said one condu'ctor of said trunk, meanscontrolled *by said space discharge device for connecting the:

two conductors of said trunk in parallel and simultaneously connectingthe said source of'coin' control current thereto for projectionrthereover to' said localoflice, and means includinga space dischargedevice in said trunk at said local office responsive to thecurrent'projected overth'e conductors of said trunk for connecting thesource of coin control current at said local office to said line toeffect the operation of the coin disposal means at said pay station.

3. In a manual telephone system, a toll office, a local ofiice, a lineterminating at said local office, a pay station on said line including acoin receptacle having coin disposal means associated therewith, a tollswitching trunk connecting said line with said toll office by way ofsaid local ofiice, a source of coin control current at said toll office,a source of coin control current at said local oflice, a relay at saidlocal office, a signal at said toll office, means at said toll ofiicefor connecting the coin control current source thereat to said trunk,space discharge means responsive to the connection of said source tosaid trunk for causing current from said source to be transmitted oversaid trunk to said local ofiice, means at the local office responsive tothe current transmitted over said trunk for connecting the coin controlcurrent source at said local ofiice in series with said relay to saidline to effect the operation of the coin disposal means at said paystation, and means controlled by said relay for operating said signal.

4. In a manual telephone system, a local eX- change, a pay station lineterminating at said local exchange, a station on said line includingmeans for receiving coins, coin collect and refund batteries at saidlocal exchange, a distant toll office, coin collect and refund batteriesat said toll office, a toll switching trunk having a plug-ended incomingend in said local exchange and a jack-ended outgoing end in said tolloffice, means including the plug end of said trunk for completing aconnection from said toll office to said line by way of said trunk,means at said local exchange for controllin the connection of the coincollect and refund batteries thereat to said line by way of the plug endof said trunk, said means including a space discharge device responsiveto the connection of coin control battery in parallel to the conductorsof said trunk at said toll ofiice, means at said toll ofiice forconnecting either of the coin control batteries thereat to one of theconductors of said trunk by way of the jack end thereof, means includinga space discharge device at said toll office responsive to theconnection of either of the coin control batteries to the said one trunkconductor for connecting the same said coin control battery to both theconductors of said trunk in parallel to effect the response of the spacedischarge device at said cal exchange, and the consequent operation ofthe coin receiving means at said station.

5. In a manual telephone system, a local exchange, a subscriber's lineterminating in said exchange, a station of the pay station type on saidline including means for receiving coins, coin control batteries at saidexchange, a distant toll office, coin control batteries at said tollofiice, means including a toll switching trunk for completing acommunication connection between said distant toll ofiice and saidsubscribers line by way of said local exchange, means including a vacuumtube in said trunk at said toll office responsive to the connection ofone of said coin control batteries at said toll ofiice to one of theconductors of said trunk for superimposing on the conductors of saidtrunk a simplex circuit and for simultaneously connecting the said oneof said coin control batteries at the toll office to the midpoint ofsaid simplex circuit to efiect the transmission of coin control currentover the conductors of said trunk in parallel, means including a vacuumtube at said local exchange responsive to the coin control currenttransmitted from said toll ofiice over said trunk conductors, and meanscontrolled thereby for connecting a corresponding coin control batteryat said local exchange to said line to effect the operation of the coinreceiving means at said station in a corresponding manner.

6. In the telephone system, a toll oflice, a local exchange, a tollswitching trunk extendin between said ofiice and said exchange, a sourceof coin control current at said toll office, a source of signalingcurrent at said toll oiiice, means responsive to the connection of saidsource of coin control current to one conductor of said trunk forcompleting a coin control circuit over both conductors of said trunk inparallel to said local exchange, said means also being capable ofoperation in response to the application of current from said signalingcurrent source to said trunk, and means responsive to the connection ofsaid ignaling current source to said trunk for rendering the response ofsaid first means to the connection of said signaling current sourceinefiective to complete the said coin control circuit over theconductors of said trunk in parallel.

GUSTAVE ADOLPH ANDERSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,904,252 Robb Apr. 18, 19331,946,228 McKim Feb. 6, 1934

